1. Field of the Invention
The present invention relates to a white key for use in a keyboard instrument, such as a piano.
2. Description of the Related Art
Conventionally, as a white key for a keyboard instrument, there has been known one disclosed e.g. in Japanese Laid-Open Patent Publication (Kokai) No. 2009-145731. As shown in FIG. 6A, this white key 50 includes a wooden key body 51 and a synthetic resin-made key cover 52 bonded to the key body 51. The key cover 52 comprises an upper cover portion 52a that covers a portion of the key body 51 from a front end to a center or its vicinity of the key body 51, and a front cover portion 52b that covers a front end face of the key body 51. The front cover portion 52b is formed in a rib shape integrally with the upper cover portion 52a such that it extends perpendicularly downward from the lower surface of the upper cover portion 52a. With this, the upper cover portion 52a and the front cover portion 52b are formed to have an L shape in cross section.
In the case of manufacturing the white key 50 disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 2009-145731, a manufacturing method described below is generally employed. First, there are made a wooden member (hereinafter referred to as “the key body member”) which corresponds to a member integrally including key bodies 51 for one octave and a synthetic resin member (hereinafter referred to as “the key cover member”) which corresponds to a member integrally including key covers 52 for one octave and is L-shaped in cross-section. Then, after bonding the key cover member to the key body member using a clamping press and a predetermined adhesive, and cutting is performed, whereby white keys 50 for one octave are manufactured. In doing this, in a case where the synthetic resin-made key cover member is made by a general injection molding method, since the key cover member has a structure in which the front cover portion 52b is formed in a lib shape integrally with the upper cover portion 52a, when the injection molded article is cooled, a sink (sink mark) 52c is sometimes formed at a portion where the two cover portions 52a and 52b are made integral with each other, as shown in FIG. 6B, or the front cover portion 52b is sometimes warped, as shown in FIGS. 6C and 6D. Further, although not shown, the front cover portion 52b is sometimes warped about the vertical axis thereof, or an insufficient filling condition, i.e. a short, can occur where a molding resin cannot reach a portion of a mold for injection molding corresponding to an extreme end of the front cover portion 52b. When such a sink, a warpage, or a short occurs, yield and marketability are lowered, which leads to an increase in manufacturing costs.
Further, the key cover member is formed in an L shape in cross section, and hence when bonding the key cover member to the key body member, it is difficult to cause the clamping press to apply uniform pressure to the entire key cover member, which tends to cause bonding failure. In this case as well, yield and marketability are lowered, which leads to an increase in manufacturing costs. Furthermore, for the same reason, the clamping press used for bonding becomes complicated in structure and increased in size, which causes a further increase in manufacturing costs.